Digital lighting technologies, i.e. illumination based on semiconductor light sources, such as light-emitting diodes (LEDs), offer a viable alternative to traditional fluorescent, HID, and incandescent lamps. Functional advantages and benefits of LEDs include high energy conversion and optical efficiency, durability, lower operating costs, and many others. Recent advances in LED technology have provided efficient and robust full-spectrum lighting sources that enable a variety of lighting effects in many applications. Some of the fixtures embodying these sources feature a lighting module, including one or more LEDs capable of producing different colors, e.g. red, green, and blue, as well as a processor for independently controlling the output of the LEDs in order to generate a variety of colors and color-changing lighting effects, for example, as discussed in detail in U.S. Pat. Nos. 6,016,038 and 6,211,626, incorporated herein by reference.
In many lighting fixtures (or “luminaires”) that embody one or more LEDs capable of producing different colors, it may be desirable to appropriately mix the light output of such LEDs prior to the light output exiting the LED-based lighting fixture. Appropriate mixing of the LEDs may reduce the presence of any undesired chromatic nonuniformity in the light output of the lighting fixture and provide more desirable light output characteristics. In implementing mixing solutions, many lighting fixtures employ multiple large mixing chambers and/or only provide illumination from a single planar light exit opening. Such configurations may result in an undesirably large mixing solution and/or a mixing solution of limited utility.
Thus, there is a need in the art to provide an LED-based luminaire that may provide satisfactory mixing of light output from a plurality of LEDs thereof and that may optionally overcome one or more drawbacks with existing mixing solutions.